Bernie Sanders should know his socialized medicine but in an exchange on Sunday he failed when he was pressed to explain why a single-payer health care system was rejected in Vermont and California, two staunchly Democratic states:

CNN host Jake Tapper said that California and Vermont are “cobalt blue states” and asked how single-payer could be affordable at the national level if they rejected the system at the state level because of the expense:

Single-payer failed to pass in both California and Vermont after lawmakers were unable to figure out how to fund the system. Voters in Colorado also rejected single-payer last year.

Sanders pushed back against Tapper, citing “studies that he has seen,” and said that single-payer would save the average family “significant sums of money.”

“If you look at Canada’s single-payer health care system per capita, their costs are far far less than the United States,” Sanders said. ” If you look at the UK, if you look at countries around the world, all of which have different approaches to a national health care system, in every instance, they are spending substantially less per capita than we pay in the United States.”